The Scare Spreads

While there is no epidemiological evidence to show how the disease spread from animals to humans in India, Himalayan sheep are the prime suspects as Scrapie—the Mad Cow strain among sheep—has long been prevalent among them. Scrapie is also said to be found in Kasauli, Himachal Pradesh, where the Government-run Central Research Institute produces the commonly available rabies vaccine from the brains of live sheep. A full 14-injection course of this vaccine is available for Rs 100 against Rs 250 for the tissue-culture vaccine. "About 40,000 persons are vaccinated against rabies each year," says senior virologist Subhash C. Arya, who caused a minor flutter by suggesting that CJD could be transmitted through the vaccine.

S.K. Shankar, co-author of the NIMHANS study, however, disputes Arya's contention: "Most of the 30 cases reported and studied till 1990 were vegetarians and had not been inoculated with rabies vaccine. Besides, rabies vaccine used in Bangalore and Bombay are manufactured at Belgaum and Hyder-abad and not in Kasauli where Scrapie is prevalent." He argues that, unless conclusively linked to CJD, the sheep-brain vaccine, which is the cheapest available, should not be phased out.

CJD was discovered independently by German scientists, Hans Creutzfeldt and Alfons Jakob, 75 years ago, but its causative agent is yet to be found. The widely held hypothesis points to the Prion protein, found in all animals but whose function is unknown, which at times turns 'abnormal' and accumulates in the central nervous system, thus damaging it. A rival theory claims it may be a bacterium.

The disease has an incubation period ranging from 15 months to 20 years or more, and results in rapidly progressive dementia, spasms, mycolic jerks coupled with spasticity, wasting and coma. It is fatal and has no cure. While in most cases the mode of transmission is unknown, persons are known to have contracted it from transplant of tissues, body organ transplants, injection of growth hormones prepared from human pituitary glands, and re-use of chemically disinfected electrodes previously implanted to study brain waves of CJD patients as also of equipment used for root canal therapy by dentists.

However, unlike in the West where CJD has mostly afflicted the 65-plus age group, in the NIMHANS study, of the 30 cases, 25 were aged below 65—of which 16 were below 55 (see chart). Ten housewives, five agriculturists, one doctor, two teachers and two labourers were among the victims, though there is no evidence as to how they contracted the disease. "Earlier we considered it a degenerative disease. In the light of the revelations we will need to study and examine it better. But, our health priorities lie elsewhere for, as against 30 known CJD cases in India in 20 years, we have 1,300 people dying of TB every day," says K.K. Datta, director, National Institute of Communicable Diseases, Delhi.

The hardest hit by the NIMHANS findings is the Agriculture Ministry, as the economic implications of Mad Cow disease in the West are infinitely more severe than its health implications. On April 9, K. Rajan, secretary, Department of Animal Husbandry and Dairy, summoned a high-level meeting of veterinary and health experts to assess the implications, if any, on Indian livestock which contributes 6 per cent of the Gross Domestic Product comprises 26 per cent of the agriculture sector's share of the national income. Simultaneously, the Union Health Ministry is setting up a special task force to study the extent and manner of transmission of CJD.

"We will not face the kind of crisis as in Britain as the majority of Indian livestock are free grazing and only a small proportion are given compounded cattle feed. Here, mainly fish meal is used rather than bone meal which caused the Mad Cow disease in UK," says a senior Agriculture Ministry official.

However, Arya says that with liberalisation, as western animal husbandry techniques are being imported, infected bone meal may be fed to Indian livestock which may then spread the disease. The worst, he warns, may be yet to come.?